The present invention relates to the field of transistor based radio frequency (RF) circuits, and in particular to such circuits having, collectively, multiple transistors with interconnected signal grounds, and that are each biased by current conducted by resistance devices coupling the transistors to ground.
Conventionally, a transistor is biased by applying a voltage to a current-carrying terminal, such as a drain of a field-effect transistor (FET), and a related bias to a control terminal, such as the gate, with the other current-carrying terminal, in this case the source, coupled to a common reference potential, such as ground. Other configurations are also possible, such as a common gate or common drain configuration.
Such conventional circuits require isolation between transistors and external circuits in order to isolate the bias voltages to each transistor. These designs require multiple voltage supplies. Additionally, a capacitor is required between the transistor and ground in order to maintain the bias on the transistor.